Group Elements

Which one of the following names does not correspond to a group of elements in the periodic table?

• Alkali

• Group VII

• Alloys

• Halogens

Which of the following observations does not apply to group I elements?

• They are relatively soft metals

• The corrode quickly when exposed to air

• They react very quickly with water releasing hydrogen gas

• They produce acidic solutions in reaction with water

Which statement about the alkali metals is correct?

• Potassium is more dense than lithium

• Lithium has a higher density than sodium

• Potassium is less reactive than sodium

• The melting point of sodium is higher than lithium

The reactivity of halogens decreases moving down the group. Which statement explains this observation?

• Decreasing distance between the nucleus and outer shell makes it easier for the atom to attract electrons

• Increasing distance between the nucleus and outer shell makes it easier for the atom to attract electrons

• Decreasing distance between the nucleus and outer shell makes it harder for the atom to attract electrons

• Increasing distance between the nucleus and outer shell makes it harder for the atom to attract electrons.

The reactivity of the alkali metals increases moving down the group. Which statement explains this observation?

• Decreasing distance between the nucleus and outer shell makes it easier for the metals to lose their valence electrons

• Increasing distance between the nucleus and outer shell makes it harder for the metals to lose their valence electrons

• Increasing distance between the nucleus and outer shell makes it easier for the metals to lose their valence electrons

• Decreasing distance between the nucleus and outer shell makes it easier for the metals to lose their valence electrons

Which row describes the properties of fluorine?

• A

• B

• C

• D

Astatine is a radioactive Group VII element which is extremely unstable, making it difficult to study. The physical and chemical properties of astatine can only be estimated.

Which row most likely describes the properties of astatine?

• A

• B

• C

• D

The Group I metals show trends in both their physical and chemical properties.

(a) (i) How do their melting points vary down the group?

(ii) Which element in the Group has the highest density?

(iii) All Group I metals react with cold water. Write the balanced chemical equation between Rb and water.

Rubidium, Rb, is a Group I element. It has similar physical and chemical properties to other elements in Group I.

(a) Predict how many electrons are there in th outer shell of rubidium atom

(b) When Rb is added to cold water a reaction occurs.

(i) Suggest two observations that would ne made when Rb is added to cold water?

(ii) What would be the color of the solution if methyl orange was added to it after the reaction?

(iii) Write a chemical equation for the reaction between Rb and water

(iv) Suggest one safety measure that should be used when rubidium is added to cold water

Put the Group I elements, Cs, Li, K, Rb and Na in their order of reactivity with water.

________, ________, ________, ________, ________